PL/SQL - Constants and Attributes

A constant has to declared and initialized in the declare block only using CONSTANT keyword

Constant Value cannot be changed

declare

r CONSTANT number :=100;

begin

/* r := r + 100; Not possible*/

dbms_output.put_line(r);

end;

/*Assigning value to variable from a column of a table using select into clause*/

declare

salary number;

begin

Select sal Into salary from emp

where ename = 'HAREESH;

dbms_output.put_line('Salary of HAREESH is '|| salary);

end;

/* Selecting ename,sal from emp

Use of more than one columns value with Into clause*/

declare

empname varchar2(50);

salary number;

begin

select ename, sal Into empname, salary

from emp

where ename = 'HAREESH';

dbms_output.put_line(empname);

dbms_output.put_line(salary);

end;